Electric switch



July 22, 1947 A. K. wHYTE Erm. 2,424,527

ELECTRIC SWITCH Filed Aug. l0, 1946 PLQ. l.

vwventows: Alewvwdev" Pfwhytg,

mmm JAldis, f' 1.x .1 I l THW' Attorney. m

` positions. i

' Patented July 22, 1947 marmo SWITCH `skimmer x. wiiy fana william J.mais, 'r0- ronto, ntario, Cansdmauignors `to General Electric Company, acorporation of New York Applicaties. samt 1o, 194s, semina-esatta' i In"September 10. 1945 Our invention rrelates to electric switches and moreparticularly to a push buttontypeswitch operable with a snap action toclosed and opened It is lthe obliectof our invention to provide a novelsnap action push button type electric switch of an economical`construction having aminimum number of parts, which is reliable inoperation and which tion.

For a completefunderstanding of our invention reference should be had tothe ,following detailed descriptiontaken in comunction withtheaccompanying drawings of a switch in accordance with our invention inwhich like reference characters designatelike parts andin which Fig. 1isa plan is protected against accidental operaf view of an electric.switchembodying our invention; Fig. 2 is a cross section on the lineA-A of the switch shown in Fig. 1, the switchmechanism being in the ofl'position: and Fig. 3 is a view similar to Fig. 2except the switch is inon" pition.

Referring to the drawings, a disc lo of msnm ing 4material constitutes abase. `A concentric vcircular `ridge Il, in the formin cross-section ofan inverted `V, projects integrally from the top surface of the disc.The apex ofthe ridge Il is spaced a substantial distance -from the`outer periphery of the disc, as shown in the `drawings about one thirdof the radius of the disc. `A Vpair of spring contact strips I2 and ilrespectively are riveted to thecentral portion of thebase Il., theirfree ends in overlapping relation one above an flange It dennin'ganopening. The ange 2l provides a bearing surface for guiding a pushbutton Il of insulating material mounted therein, A ilat spring ITofsubstantial width 'and slightly longer than the inside diametextof theunit Il is mounted in airecess 2l in the sidewall 2| thereof.` Thisspring-retaining recess 2l is provided by corrugations extending aroundtheperiphery ofK the cup wall 2l. The

spring 21 accordinglywhen sprung into the recess 2l extendsdiametricallyacross'the cup in any radial position in which it may beinserted and due to its length with respect to the cup it assumes` oneoi two bowed positions` In the upper bowed position of the spring shownin Fig. 3, it engages the bottom of the push button 2l and holds it initsupper position with its shoulders 2l engaging the `under side ofbottom wall of the cup Il below the flange 2l. When the unit it isassembled on the base member l., it is `supported thereon as shown in'Figs. `i. and 3 by i `tlie spring 21 resting on diametrlcally oppositesections of the ridge I`l-with the push button lying directly above thecontactbutton l'l. The ridge Il therefore provides ya pair of fulcrumsspacedfromthe restrained ends of the spring.

A casing generally indicated at 3l is secured to the base It.Thecasingconsists of a cylinf drical wall 3i with its upper end turnedinwardly the other and normally spaced apart. A recess Il is provided`centrally in theside of the disc remote from the .contacts toaccommodate the rivet heads within the plane of the bottom of the ldisc. A pair of grooves I5 inthe bottom of the disc Ill extend radiallyfrom the recess Il to the periphery to accommodate lead wires Il, forthe contacts. A button Hof insulating material is secured to thetopsurface `of the upperL contact strip I3.

A carrier unit generally designatedat I0 is mounted on the base Ill`whereby the spring con tacts I2 and I3 may be closed and maintainedclosed and whereby` the unit may be independentproviding a downwardlyextending ilange l2 with a shoulder Il between them. The base Il may beconveniently secured in the casing Il by integral tangs lt formed on thebottom edge of the wall Il and deformedA to press it against a` ridge llrolled in the Awall Il. -A cover plate 3l which maybe of insulatingmaterial such as hard fibre is interposed between the tangs ll and thebottom ofthe base Il. The finternal diameter of the flange I2 isslightly greater than the external diameter of the vertical wall Il ofthe unit II towhich it acts as a bearing and guiding surface.

When the push button Il is depressed from its position shown in' Fig.2,`the spring 2l is deformed downwardly about the fulcrums provided bythe ridge Il. When deformed sumciently its central v partbetweenitssupports on theridge il passes ly actuated to release the contacts. Theunit 2l` j consists of a. cup-shaped member' havinga side wall 2l. Thebottom of the cup-shaped member 20 is shaped to provide an `annularshoulder 22 extending inwardly fromthe wall Il at right angles thereto,then an annular wall Il oi substantial height `extending upwardly fromthe j wall 22 in a direction axially oi the cup, then a portion bentdownwardly and inwardly providing an annular shoulder 24, andterminating in upwardmotion. The contacts are held in closed overcentrewith a snap action and engages the insulatingbutton Il on the spring il4pressing it downwardly into engagement with the spring I2vtherebyclosing the circuit with a wiping action.

During the operation above described. .the outer ends of the spring 21beyond the supporting ridge l lare permittedto move upwardly carryingwith them the member 2. till the wall 22 thereof engages thelower end ofthe ilange I2 oi the casing whichv acts as a stop `for `the member 2l inits the ends of the spring position as illustrated in Fig. 3 by thelower bowed form which the spring assumes and the stop provided by theengagement of the wall 22 with the wall l2.

To open the switch contacts, the carrier unit acts as an operatingmember.' Pressure on the annular shoulder 2l of unit 20 is transmittedto 21 causing the spring to deform fulcrumed by the ridge Il, and thesection or spring 21 between the pair of fulcrums passes overcentre andassumes position illustrated in Fig. 2, thus permitting the contacts I2and Il to assume their open position The dimensions of and casing areselected so that in both the operative positions ofthe push button andthe member 20 as illustrated, their exposed top surfaces are beneath thelevel of the shoulder 13 of thecasing. This militares against accidentaloperation of either of themembers.

It will be observed that we have provided a rugged switch of a fewsturdy parts whichare easily assembled and certain inaction. (The singlespring is positively actuated by two separate devices whereby whenassembled in its carrier member it assumes either an upper or lowerbowed position. Each ofthe separate devices when actuated causes thespring to snapA from one position to the other. y

While we have shown a particular embodiment of our invention it will, ofcourse, be understood that we do not wish to be limited thereto sincevarious modifications may be made and we contemplate by the appendedclaims to cover any such modifications as i'all within the true spiritand scope of our invention.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

l. An electric switch comprising a fiat spring restrained in a memberwhereby it Amay assume either an upper or a lower bowed position, meansQn said member to operatesaid spring from its upper to its lower bowedposition, said spring mounted on a pair of spaced fulcrum points wherebypressure on said member causes movement of said spring from its lower toits upper position, means limiting the movement of said member in adirection away from` the said fulcrum points, and contacts arranged tobe closed by said spring when it tions and to be opened when said springis in the other of its bowed positions.

2. The device-as claimed in claim 1 in which a pair oi contacts normallyspring biased to open position are arranged between the fulcrum pointsand located in a position to be moved to closed position when saidspring assumes its lower bowed position, g

3. The device as claimed in claim l in which the operating means onthermember is a push button supported for reciprocal action thereon.

4. An electric switch comprising a pair of relatively moving contacts,means to operate the contacts to open and closed positions comprising afiat spring restrained in a carrier whereby it may assume either anupper or a lower bowed position, an operating member mounted on saidcarrier and engaging the middle portion of said spring and movable todeform said spring and cause it to pass from its upper to its lowerbowed position, a pair of fulcrums one on each side of said contacts,said spring resting on Vvsaid fulcrums at points spaced from each endthereof, said carrier mountedV to permit movement thereof towards andaway from the pair of fulcrums its upper bowed the push button, unit2lil is in one of its bowed posi-v.

whereby pressure on the carrier will cause the spring to deform from itslower bowed position and assume its upper position.

5. A push button type electrioswitch comprising a base carrying a pairof spring biased nor- -mally open contacts, an operating member carsaidmetal strip to its upper position thereby releasing said spring biasedcontacts to their normally open position.

6. A 'push button type electric switch comprising a base carrying atleast one contact and having a pair of diametrically opposed raisedfulcrum points near its outer periphery, a at spring resting on saidfulcrum points, a vertically movable carrier member acting as oneoperating member and having a diameter substantially less than thelength of said flat spring strip, said carrier having diametricallyopposed recesses in its inner walls to restrain said spring in either anupper or lower bowed position, a centrally defined recess in saidcarrier member, a second operating member protruding throughV saidcentrally defined recess and resting on said spring when said spring isin-its `upper bowed position, an outer case enclosing said operatingmembers and said base.

7. An electric switch comprising a base member having an annular ridgeprojecting from the upper surface thereof, a pair of contacts normallyspring biased to open position located on the base centrally of the saidannulus, an operating member supported on said base for operating saidcontacts to closed and opened positions comprising a carrier unit havinga fiat spring mounted thereonV whereby it is restrained to assume eitheran upper or a lower bowed position, a push button supported in saidcarrier unit in a manner to engage the middle portion of said spring,and an enclosing casing provided with means to guide said carrier unitin a direction to and from the base, said carrier unit being located insaid casing with said spring resting on diametrically opposite points ofsaid annular fulcrum with the contacts within the range of movement ofthe central portion of said spring.

8. An electric switch comprising a base having an annular ridgeprojecting from the upper surface thereof, a casing secured to the base,said casing having a circular side wall turned inwardly at its upperedge to provide a circular flange parallel therewith and spaced abovesaid ridge, a switch operating member comprising a cup-shaped shellhaving an annular wall portion cooperating with said inturned flange forguiding it towards and away from the base, a fiat spring restrainedbetween the side walls of said shell whereby the spring may assumeeither an upper or a lower bowed position, a -push button centrallylocated in the bottom of said cup-shaped shell and engaging the middleportion of said spring, the cup-shaped shell and the annulus beingproportioned and arranged whereby said spring rests on diametricallyopposite portions of base within the ange of movement of the centra]portion of said spring. UNITED STATES PATENTS ALEXANDER K. WH'YTE.Number Name Date WIHIIAM J- ALDIS- 5 1,939,286 spencer 1 Dec. 12, 19332,409,483 Gandelt OCE. 15, 1946 REFERENCES CITED 2,381,335 Moorhead Aug.7, 1945 The following references are of record in the 2.343.060 HomingFeb- 29, 1944

